This is a budgeting/planning tool to help you project cash balances into the future. It's useful when expenses are incurred in different months than they are paid, such as heavy credit card users or people with reimbursements.
Your data is stored in a local file that is only accessible by you. No one else can see your data. Thanks to the magic of pyscript.net this is a static website, there's no server to collect data other than Google Analytics.
Create Accounts such as Checking and Savings, then create Recurring Events to represent things like rent, paychecks, or semi-annual insurance. For variable events use a placeholder value, as the amount for a given transaction becomes known edit it from the Calendar tab.